Hi Newsguy - very good question - you can take a look at our sister site MarketingFind.com as we have an affiliates category there (
http://www.marketingfind.com/showcases/affiliate/). These are more places that vendors come to find places to push their products through networks.
As far as different affiliate programs go - there is a good company here (partnercentric.com) that has their own affiliate programs listed, thus if you have a strong audience of webtraffic that is focussed on a certain niche you can visit these focussed affiliate programs to promote them to your audience -
http://www.partnercentric.com/programs.shtml
Either way, call Linda Woods at partnercentric.com she can probably help you.
jon